Opportunity has been investigating the rock known as "Marquette Island". The rock abrasion tool (RAT) was used to grind a 1.5 millimeters (0.06 inch) into this very hard rock for further investigation by the other rover instruments.

On Sol 2110 (Dec. 24, 2009), the RAT itself was imaged to determine the amount of remaining grind bit. Then, a microscopic imager (MI) mosaic was performed on the RAT hole in Marquette Island. Finally, the Mössbauer (MB) spectrometer was positioned on a different rock target for a long integration.

The plan ahead is to collect an alpha particle X-ray spectrometer (APXS) spectrum and a MB spectrum from the RAT hole, before resuming the drive toward Endeavour crater.

As of Sol 2110 (Dec. 24, 2009), Opportunity's solar-array energy production was 315 watt-hours with an atmospheric opacity (tau) of 0.491 and a dust factor of 0.509. Total odometry was 18,927.56 meters (11.76 miles).

sols 2097-2103, December 17-23, 2009: Grinding at Target 'Peck Bay'

Opportunity has been investigating a rock known as "Marquette Island." On Sol 2097 (Dec. 17, 2009), Opportunity used her robotic arm (instrument deployment device, or IDD) to place the rock abrasion tool (RAT) on a target called "Peck Bay" on the rock. On Sol 2100 (Dec. 20, 2009), the RAT ground about 0.8 millimeter (0.031 inch) into Peck Bay. This two-step process for deployment of the RAT was made necessary by loss of the instrument's Z-axis encoder on Sol 1759 (Jan. 4, 2009).

On Sol 2103 (Dec. 23, 2009), Opportunity ground an additional 0.7 millimeter (0.028 inch) into to Peck Bay, bringing the total depth to about 1.5 millimeter (0.06 inch). Because Marquette Island is rather hard, grinding deliberately advances slowly. The team is planning at least one more grind, with a goal of bringing total depth to about 2 millimeters (0.08 inch).

The elevation mirror shroud of the miniature thermal emission spectrometer (Mini-TES) is being opened when appropriate with the expectation of eventual dust cleaning. No dust cleaning of the mirror has been noted yet.

As of Sol 2103 (Dec. 23, 2009), Opportunity's solar-array energy production was down to 336 watt-hours, with an atmospheric opacity (tau) of 0.490 and a dust factor of 0.520. Total odometry remained at 18,927.56 meters (11.76 miles).

sols 2091-2096, December 11-16, 2009: Preparing to Grind

Opportunity has been investigating the rock known as "Marquette Island," which has been of great interest. Assessments of its composition suggest that it might be ejecta from deep within Mars.

The plan is to position the rover to be able to perform a rock abrasion tool (RAT) grind on an accessible surface target on Marquette. On Sol 2093 (Dec. 13, 2009), Opportunity drove about 10 meters (33 feet) around the rock to position an accessible rock surface within reach of the robotic arm (instrument deployment device, or IDD). On Sol 2095 (Dec. 15, 2009), the rover performed a 5-centimeter (2-inch) bump to set up for RAT grinding.

The elevation mirror shroud of the miniature thermal emission spectrometer (Mini-TES) is being opened when appropriate with the expectation of eventual dust cleaning. No dust cleaning of the Mini-TES mirror has been noted yet.

As of Sol 2096 (Dec. 16, 2009), Opportunity's solar-array energy production is 354 watt-hours, with an atmospheric opacity (tau) of 0.462 and a dust factor of 0.528. Total odometry is 18,927.56 meters (11.76 miles).

sols 2080-2090, November 29 - December 10, 2009: Another Side of 'Marquette'

Opportunity has been investigating a rock known as "Marquette Island."

On Sol 2086 (Dec. 6, 2009), the rover backed away and then drove about 5 meters (16 feet) around Marquette Island to image other parts of the rock. On Sol 2089 (Dec. 9, 2009), Opportunity performed a 5-meter (16-foot) approach to the rock to position the rover for an in-situ (contact) study of a different part of the rock than it had touched earlier. On the next sol, the robotic arm (instrument deployment device, or IDD) collected a mosaic of images by the microscopic imager (MI) and then placed the alpha particle X-ray spectrometer (APXS) on a new location on the rock for a long integration.

The elevation mirror shroud of the miniature thermal emission spectrometer (Mini-TES) is being opened when appropriate with the expectation of eventual dust cleaning. No dust cleaning of the Mini-TES mirror has been noted yet.

As of Sol 2090 (Dec. 10, 2009), Opportunity's solar-array energy production is 359 watt-hours, with an atmospheric opacity (tau) of 0.498 and a dust factor of 0.529. Total odometry is 18,917.41 meters (11.75 miles).

With the temporary loss of relay operations for a few sols because of the Odyssey spacecraft safe-mode, Opportunity has limited the collection of other science data and continued with the low-data volume MB integrations. The miniature thermal emission spectrometer (Mini-TES) elevation mirror shroud is being opened when appropriate with the expectation of eventual dust cleaning. No dust cleaning of the Mini-TES mirror has been noted yet.

As of Sol 2079 (Nov. 28, 2009), the solar array energy production was 360 watt-hours with an atmospheric opacity (tau) of 0.508 and a dust factor of 0.529. Total odometry was 18,906.82 meters (11.75 miles).

sols 2069-2075, November 18-24, 2009: 'Marquette' Study Continues

Opportunity has been investigating the rock known as "Marquette Island" over the last couple of weeks. This target is proving to be something unique that Opportunity has not encountered in more than 2000 Sols of exploring Mars.

The science team is theorizing this rock could be either be a type of meteorite that Opportunity has never seen before or it could be ejecta from deep within the Martian crust that might provide clues to Mars' geologic past. The rover completed Mössbauer (MB) spectrometer and Alpha-Particle-X-Ray Spectrometer (APXS) measurements on a rock target named "Peck Bay" last week. Peck Bay was also lightly brushed by the Rock Abrasion Tool (RAT), which removed a layer of dust on the rock to expose the material beneath.

To gain additional information on Marquette Island, Opportunity has repeated the same set of measurements on an adjacent target called "Islington Bay." The miniature thermal emission spectrometer (Mini-TES) elevation mirror shroud is being opened when appropriate with the expectation of eventual dust cleaning. No dust cleaning of the Mini-TES mirror has been noted yet.

As of Sol 2075 (Nov. 24, 2009), the solar array energy production was 371 watt-hours, with an atmospheric opacity (tau) of 0.512 and a dust factor of 0.520. Total odometry was 18,906.82 meters (11.75 miles).

sols 2063-2068, November 12-17, 2009: 'Marquette' Study Begins

Opportunity has been investigating a rock called "Marquette Island."

The rover approached the rock on Sol 2063 (Nov. 12, 2009) and has been using the Mössbauer (MB) spectrometer and alpha particle X-ray spectrometer (APXS) to collect measurements on the rock to assist in determining the rock composition. Opportunity also has taken close-up images using the microscopic imager (MI) on Sol 2065 (Nov. 14, 2009).

The rock abrasion tool (RAT) on the arm will lightly brush the rock to reveal the surface beneath the layer of dust. After receiving the results of the RAT brush, the science team will decide whether to look even deeper into the rock by grinding a couple of millimeters (about a tenth of an inch) down into it and performing additional science observations.

There has also been extensive imaging of the surrounding rocks around Marquette. The elevation mirror shroud of the miniature thermal emission spectrometer (Mini-TES) is being opened when appropriate with the expectation of eventual dust cleaning. No dust cleaning of the Mini-TES mirror has been noted yet.

As of Sol 2068 (Nov. 17, 2009), Opportunity's solar-array energy production was 385 watt-hours, with an atmospheric opacity (tau) of 0.482 and a dust factor of 0.530. Total odometry was 18,906.82 meters (11.75 miles).

sols 2057-2062, November 6-11, 2009: Approaching "Marquette Island"

Opportunity is still heading south before the turn east to head toward Endeavour Crater. The right front wheel is exhibiting elevated motor currents. So, the plan is to find a place to stop and rest the actuator while conducting some some contact science.

On Sol 2058 (Nov. 7, 2009), the rover began a 15-meter (49-foot) approach to a candidate rock target called "Marquette Island." On Sol 2061 (Nov. 10, 2009), Opportunity bumped about 4 meters (13 feet) to position Marquette Island within the work volume of the rover's robotic arm (instrument deployment device, or IDD). The rover continues to command the miniature thermal emission spectrometer (Mini-TES) elevation mirror open each sol in an attempt to clear some of the putative dust off the elevation mirror. To date, no improvement in the Mini-TES has been observed.

As of Sol 2062 (Nov. 11, 2009), Opportunity's solar-array energy production was 400 watt-hours, with an atmospheric opacity (tau) of 0.486 and a dust factor of 0.531. Total odometry was 18,905.90 meters (11.75 miles).

sols 2050-2056, October 30 - November 05, 2009: Five Drives

Opportunity continues to make good progress driving. The rover continued to drive south on sols 2050, 2051, 2054, 2055 and 2056, (Oct. 30, 31, Nov. 3, 4 and 5, 2009) totaling over 260 meters (853 feet).

The right-front wheel is now showing a return of elevated motor currents. The plan ahead is to rest the actuator during an extended stop for an in-situ (contact) science campaign. The rover continues to command the miniature thermal emission spectrometer (Mini-TES) elevation mirror open each sol in an attempt to clear some of the putative dust off the elevation mirror. To date, no improvement in the Mini-TES has been observed.

As of Sol 2056 (Nov. 5, 2009), Opportunity's solar-array energy production is 376 watt-hours, with an atmospheric opacity (tau) of 0.548 and a dust factor of 0.527. Total odometry is 18,886.95 meters (11.73 miles).

sols 2043-2049, October 22-29, 2009: Southbound Progress

Opportunity has been making good progress driving. After completing a survey of meteorites recently, Opportunity has turned south around the point of a large ripple field. Eventually, the rover will resume heading east towards Endeavour crater.

The rover drove southward on sols 2043, 2045, 2047, 2048 and 2049 (Oct. 22, 25, 27, 28 and 29, 2009), totaling over 280 meters (918 feet). The rover commands the miniature thermal emission spectrometer (Mini-TES) elevation mirror open each sol in an attempt to clear some of the putative dust off the elevation mirror. To date, no improvement in the Mini-TES has been observed.

As of Sol 2049 (Oct. 29, 2009), Opportunity's solar-array energy production is 419 watt-hours, with an atmospheric opacity (tau) of 0.580 and a dust factor of 0.571. Total odometry is 18,622.44 meters (11.57 miles).

sols 2036-2042, October 15-21, 2009: A Meteorite Called 'Mackinac'

Opportunity surveyed another meteorite and has been driving ambitiously to the west and south to get around a field of large ripples. On Sol 2038 (Oct. 17, 2009), Opportunity circumnavigated a meteorite called "Mackinac," conducting mid-drive imagery of the rock, then drove away covering about 70 meters (230 feet) to the southwest.

On Sol 2040 (Oct. 19, 2009), the rover drove approximately 72 meters (236 feet) to the southwest. It completed a similar 71-meter (233-foot) drive on the next sol, again to the southwest.

Motor currents in the right-front wheel continue to remain well behaved. The rover commands the miniature thermal emission spectrometer (Mini-TES) elevation mirror open each sol in an attempt to clear some of the putative dust off the elevation mirror. To date, no improvement in the Mini-TES has been observed.

As of Sol 2042 (Oct. 21, 2009), Opportunity's solar-array energy production is 430 watt-hours, with an atmospheric opacity (tau) of 0.586 and a dust factor of 0.5575. Total odometry is 18,322.03 meters (11.39 miles).

sols 2029-2035, October 08-15, 2009: Finished with 'Shelter Island'

Opportunity completed its survey of the meteorite called "Shelter Island".

On Sol 2029 (Oct. 8, 2009), the rover completed the in-situ (contact) science campaign on the meteorite's surface with a microscopic imager (MI) mosaic and an alpha particle X-ray spectrometer (APXS) placement for integration. On Sol 2031 (Oct. 10, 2009), the robotic arm (instrument deployment device, or IDD) was lifted from the meteorite and some final documentary images were collected by the panoramic camera (Pancam). On Sol 2032 (Oct. 11, 2009), the rover performed a 10-meter (33-foot) circumnavigation of the meteorite to image and document the backside.

On Sol 2034 (Oct. 14, 2009), Opportunity left "Shelter Island" and headed northwest driving 64 meters (210 feet) backwards toward another large rock (more than half a meter or 1.5 feet). With that drive, Opportunity crossed the 18 kilometer mark in total odometry. Motor currents in the right-front wheel continue to remain well behaved.

As of Sol 2035 (Oct. 15, 2009), Opportunity's solar array energy production was 446 watt-hours, with an atmospheric opacity (tau) of 0.591 and a dust factor of 0.562.

Opportunity has discovered another large (0.5-meter) meteorite. The rover began the approach to this new meteorite, called "Shelter Island," with a 28-meter backward drive on Sol 2022.

On Sol 2024, Opportunity turned around with a 2-meter drive to face the meteorite. A final 1-meter bump on Sol 2027 put the meteorite within the work volume of the rover robotic arm (IDD). In-situ (contact) measurements are now being planned.

Motor currents in the right front wheel continue to remain well behaved.

As of Sol 2028, the solar array energy production was 449 watt-hours with an atmospheric opacity (tau) of 0.638 and a dust factor of 0.5695.

Total odometry as of Sol 2028: 17,962.44 meters

sols 2015-2020, September 24-29, 2009: Westbound Around Risky Region

Opportunity has been driving, driving, driving. The rover drove three out of the last six sols, making good progress along the path to Endeavour crater.

Each drive was backwards, continuing to head west in order to avoid a large region of potentially risky dune ripples. Eventually, the rover will turn south, then east, to head directly toward Endeavour. On Sols 2015, 2017 and 2020 (Sept. 24, 26 and 29, 2009), the rover drove 70.75 meters (232 feet), 71.85 meters (236 feet) and 70.62 meters (232 feet), respectively. Rover odometry is nearing the 18-kilometer mark.

Motor currents in the right front wheel remain well behaved.

As of Sol 2020 (Sept. 29, 2009), Opportunity's solar-array energy production was 461 watt-hours with an atmospheric opacity (tau) of 0.677 and a dust factor of 0.599.

Opportunity has driven four out of the last six sols, making way to Endeavour crater.

On sols 2009, 2011, 2013 and 2014 (Sept. 18, 20, 22 and 23), the rover drove 55 meters (180 feet), 71 meters (233 feet), 70 meters (230 feet) and 59 meters (194 feet), respectively, passing 11 miles of total odometry. Each drive was backwards heading to the west to avoid a large region of potentially risky dune ripples. Eventually, the rover will turn south, then east, to head to Endeavour.

Motor currents in the right-front wheel remain well behaved.

As of Sol 2014 (Sept. 23, 2009), Opportunity's solar-array energy production is 477 watt-hours. Atmospheric opacity (tau) is 0.681, and the dust factor on the solar array is 0.603. Total odometry is 17,717.33 meters (11.01 miles).

sol 2001-2008, September 09-17, 2009: Departing Block Island

Opportunity completed the circumnavigation and full-circle imaging of the large meteorite "Block Island" and has resumed the long drive to Endeavour crater.

On Sol 2001 (Sept. 9, 2009), the rover moved 9 meters (30 feet) around the meteorite to the fourth and fifth out of six planned positions. On the next sol Opportunity reached the sixth and final position around Block Island with a 3-meter (10-foot) bump.

On Sol 2004 (Sept. 12, 2009), Opportunity departed Block Island and headed away with a 70-meter (230-foot) drive to the west. The westward direction is to head around a region of large dunes before turning south and east toward Endeavour. Two additional 70-meter (230-foot) westward drives were accomplished on sols 2006 and 2007 (Sept. 14 and 16, 2009; due to Mars sols being nearly 40 minutes longer than Earth days, no Opportunity sol number matched the criterion used here of noon at Opportunity's location falling on Sept. 15 in Los Angeles).

As of Sol 2008 (Sept. 17, 2009), Opportunity's solar-array energy production is 499 watt-hours, with an atmospheric opacity (tau) of 0.565 and a dust factor improved to 0.582. Total odometry is 17,462.20 meters (10.85 miles).

sol 1995-2000, September 03-08, 2009: Circling the Meteorite

Opportunity has commenced circumnavigation and full-circle imaging of the large meteorite "Block Island".

On Sol 1997 (Sept. 5, 2009), the rover moved 5.7 meters (18.7 feet) to the second of six stand-off positions around the meteorite (the first position being the initial rover location). At each location Opportunity collects a set of images with the panoramic camera (Pancam).

On Sol 1999 (Sept. 7, 2009), Opportunity drove about 4 meters (13 feet) to the third position. The plan is to complete the circumnavigation of the meteorite before departing this location.

As of Sol 2000 (Sept. 8, 2009), Opportunity's solar-array energy production is 527 watt-hours, with an atmospheric opacity (tau) of 0.475 and a dust factor improved to 0.6145. The rover's total odometry is 17,238.97 meters (10.71 miles).

This week's activities for both rovers have been impacted by problems with other spacecraft. Relay support by Mars Reconnaissance Orbiter (MRO) was not available. Mars Odyssey is picking up additional rover relay passes to cover for lost MRO support.

Like Spirit, Opportunity was also affected by closure of the Jet Propulsion Laboratory on Aug. 31, 2009, due to local wildfires. Onboard run-out sequences were executed on sols 1993 and 1994 (Sept. 1 and 2, 2009). Since sol 1990 (Aug. 29, 2009), Opportunity had been collecting a very long Mössbauer (MB) integration on the target "Siahs Swamp 2," a location on the meteorite "Block Island."

As of Sol 1993 (Sept. 1, 2009), Opportunity's solar-array energy production was 439 watt-hours. Atmospheric opacity (tau) was 0.573 and the dust factor on the solar array was 0.554, meaning that about 55.4 percent of the sunlight hitting the solar array was penetrating through the dust on the array. The rover's total odometry remained at 17,229.16 meters (10.71 miles).

sol 1981-1987, August 20-26, 2009: Meteorite Examination Continues

Opportunity is continuing its contact investigation of the 70-centimeter (28-inch) meteorite called "Block Island."

On Sol 1981 (Aug. 20, 2009), the rover performed a very small rotation that moved the robotic arm (instrument deployment device, or IDD) in azimuth to reach new targets on the meteorite. On the next sol, the IDD collected a stack of microscopic imager (MI) images of new targets and then placed the alpha particle X-ray spectrometer (APXS) onto a target.

The IDD changed tools the following sol from the APXS to the Mässbauer (MB) spectrometer and placed it on the target "Siahs Swamp2" for a multi-sol integration. On Sol 1986 (Aug. 25, 2009), the MB was retracted and an ambitious MI imaging campaign, including stereo imaging, was performed on the surface of the meteorite. At the end of that, the MB was replaced for continued integration.

The shroud of the miniature thermal emission spectrometer (Mini-TES) continues to be left open on scheduled sols to allow the environment to clean putative dust contamination from the elevation mirror. No improvement in Mini-TES performance has been observed so far, but the rover has seen no wind events.

As of Sol 1986 (Aug. 25, 2009), Opportunity's solar-array energy production was 453 watt-hours with an atmospheric opacity (tau) of 0.526 and a dust factor of 0.550. The rover's total odometry was 17,229.16 meters (10.71 miles).

sol 1974-1980, August 13-19, 2009: More Targets at 'Block Island'

Opportunity is continuing its in-situ (contact) investigation of the 70-centimeter (28-inch) meteorite called "Block Island."

On Sol 1974 (Aug. 13, 2009), robotic arm (IDD) work on ground in front of the meteorite completed with a microscopic imager (MI) mosaic of pebbles called "Vail Beach" at the foot of Block Island.

On the next sol, Opportunity bumped closer to Block Island by about 40 centimeters (16 inches). This puts other meteorite surface targets within reach of the rover's robotic arm. On Sol 1976 (Aug. 15, 2009), the MI collected a mosaic of the target "Purple Patch," then placed the Mössbauer (MB) spectrometer for a long integration. On Sol 1979 (Aug. 18, 2009), the MI collected mosaics of a different target and then the arm positioned the alpha particle X-ray spectrometer (APXS).

The shroud of the miniature thermal emission spectrometer (Mini-TES) continues to be left open on scheduled sols to allow the environment to clean putative dust contamination from the elevation mirror. No improvement in Mini-TES performance has been observed so far, but the rover has seen no wind events.

As of Sols 1979 and 1980 (Aug. 18 and 19, 2009), Opportunity's solar-array energy production was 467 watt-hours with an atmospheric opacity (tau) of 0.457 and a dust factor of 0.552. The rover's cumulative odometry on Sol 1980 was 17,229.16 meters (10.71 miles).

sol 1968-1973, August 06-12, 2009: Examining 'Block Island'

Opportunity is conducting contact investigations of a meteorite called "Block Island," which is about two-thirds of a meter (2 feet) across.

On Sol 1968 (Aug. 6, 2009), the Mössbauer (MB) spectrometer was placed on the meteorite surface on a target called "New_Shoreham" for a multi-sol integration. On Sol 1970 (Aug. 8, 2009) the robotic arm (instrument deployment device, or IDD) moved the MB to a new target called "Clayhead_Swamp" for a long integration.

To check out some pebbles next to the meteorite and to line up for new targets on Block Island, Opportunity bumped backwards and then re-approached Block Island with a 2.5-meter (8-foot) movement on Sol 1973 (Aug. 12, 2009). At this new location Opportunity is positioned to investigate some very unusual features on the meteorite's surface.

The shroud of the miniature thermal emission spectrometer (Mini-TES) continues to be left open on scheduled sols to allow the environment to clean putative dust contamination from the elevation mirror. No improvement in Mini-TES performance has been observed so far, but the rover has seen no wind events.

Opportunity's solar array produced 475 watt-hours of energy on Sol 1973 (Aug. 12, 2009). Atmospheric opacity (tau) was 0.415. The dust factor on the solar array was 0.560, indicating that 56.0 percent of sunlight hitting the array penetrates the layer of accumulated dust on it. Total odometry was 17,228.74 meters (10.71 miles).

sol 1960-1967, July 29 - August 05, 2009: Meeting a Meteorite

Opportunity has arrived at the large cobble called "Block Island," which is about two-thirds of a meter (2 feet) across. A 1.5-meter (5-foot) bump on Sol 1961 (July 31, 2009) put the rock in the work volume of the robotic arm (instrument deployment device, or IDD).

From Sols 1963 to 1967 (Aug. 1 to Aug. 5, 2009), Opportunity studied a series of surface targets on Block Island using the instruments on the IDD. Resulting data confirmed that the rock is an iron-nickel meteorite.

The shroud of the miniature thermal emission spectrometer (Mini-TES) continues to be left open on scheduled sols to allow the environment to clean putative dust contamination from the elevation mirror. No improvement in Mini-TES performance has been observed so far, but the rover has seen no wind events.

As of Sol 1967 (Aug. 5, 2009), Opportunity's solar-array energy production is 491 watt-hours with an atmospheric opacity (tau) of 0.547 and a solar-array dust factor of 0.586. The rover's total odometry is 17,226.29 meters (10.70 miles).

sol 1954-1959, July 23-28, 2009: Approaching 'Block Island' Cobble

Opportunity has spied a dark, meter-scale cobble in the opposite direction from which she has been traveling. On Sol 1954 (July 23, 2009), the rover headed back toward this large coble, called "Block Island," with over a 100 meter (328-foot) drive.

In-situ (contact) analysis using the robotic arm will now begin on this 70-centimeter-size (28-inch) cobble. The miniature thermal emission spectrometer (Mini-TES) shroud continues to be left open on scheduled sols to allow the environment to clean minor dust contamination from the elevation mirror. No improvement in Mini-TES performance has been observed so far, but the rover has seen no wind events.

As of Sol 1959 (July 28, 2009), the solar array energy production was 467 watt-hours with an atmospheric opacity (tau) of 0.517 and a dust factor of 0.534.

Opportunity had been driving to the west to go around a large field of impassable dunes on her long way to Endeavour crater. On Sol 1947 (July 16, 2009), the rover drove a little over 70 meters (230 feet) to the west, slightly north.

On the next sol, the rover performed a Mars quake experiment, reading the inertial measurement unit (IMU) accelerometers while stationary. Another westward drive was accomplished on Sol 1950 (July 19, 2009), achieving almost 61 meters (200 feet).

A dark, meter-scale cobble on the surface was observed some 200 meters (some 650 feet) away to the east. This cobble, informally named "Block Island," is unusual in its size. So the rover began to backtrack to the east on Sol 1952 (July 21, 2009) with a 23-meter (75-foot) drive toward the giant cobble. With that drive, Opportunity passed 17 kilometers (10.56 miles) of total odometry.

The shroud of the miniature thermal emission spectrometer (Mini-TES) continues to be left open on scheduled sols to allow the environment to clean putative dust contamination from the elevation mirror. No improvement in Mini-TES performance has been observed so far, but the rover has seen no wind events.

As of Sol 1952 (July 21, 2009), Opportunity's solar array energy production was 493 watt-hours with an atmospheric opacity (tau) of 0.462 and a dust factor of 0.559.

Opportunity began the week positioned over exposed outcrop collecting in-situ (contact) science data and resting the right-front wheel's actuator. On Sol 1942 (July 11, 2009), Opportunity began moving again with a 67-meter (220-foot) drive. The right-front wheel motor current showed some improvement from the actuator resting and extra mobility heating.

The rover performed another long drive on Sol 1946 (July 15, 2009), covering over 70 meters (230 feet). Again, the right front wheel currents showed continued improvement. The shroud of the miniature thermal emission spectrometer (Mini-TES) continues to be left open on scheduled sols to allow the environment to clean putative dust contamination from the elevation mirror.

As of Sol 1946 (July 15, 2009), Opportunity's solar array energy production is 414 watt-hours, with an atmospheric opacity (tau) of 0.476 and a dust factor of 0.520. Total odometry remains at 16,850.66 meters (10.47 miles).

sol 1932-1939, June 30-July 8, 2009: Examining 'Absecon'

Opportunity has driven to a large expanse of outcrop to conduct in-situ (contact) science.

On Sol 1932 (June 30, 2009), the microscopic imager (MI) collected a stack of images, and then the Mössbauer spectrometer (MB) was placed on a surface target called "Absecon" for an overnight integration.

On Sol 1933 (July 1, 2009), another MI stack of images was taken, and the MB was placed again on Absecon for a multi-sol integration. On Sol 1938 (July 7, 2009), the rock abrasion tool (RAT) performed a seek-scan procedure on a surface target in preparation for brushing. This first attempt did not succeed, but a RAT seek-scan the following sol was successful.

During the week, the right-front drive actuator was rested with some active heating in an attempt to mitigate elevated motor currents seen when driving. The shroud of the miniature thermal emission spectrometer (Mini-TES) is being left open for extended periods to allow the environment to clean putative dust contamination from the elevation mirror.

As of Sol 1939 (July 8, 2009), Opportunity's solar array energy production is 429 watt-hours, with an atmospheric opacity (tau) of 0.438 and a dust factor of 0.519. Total odometry remains at 16,712.46 meters (10.38 miles).

sol 1927-1930, June 25-29, 2009: At Outcrop for Study and Rest

Opportunity has driven to an expanse of outcrop to conduct some in-situ (contact) science investigations.

On Sol 1927 (June 25, 2009), the rover ventured about 65 meters (213 feet) south toward a large expanse of outcrop seen from orbital imagery. On Sol 1930 (June 28, 2009), the rover performed a short 7-meter (23-foot) maneuver to place some candidate surface targets within the constrained work volume of the robotic arm (instrument deployment device, or IDD). On Sol 1931 (June 29, 2009), the microscopic imager (MI) collected a stack of images, and then the alpha particle X-ray spectrometer (APXS) was placed on a surface target called "Absecon" for an overnight integration.

For the period ahead, the right-front wheel's drive actuator will be rested with some active heating in an attempt to mitigate elevated motor currents seen when driving. The shroud of the miniature thermal emission spectrometer (Mini-TES) is being left open for extended periods of time to allow the environment to clean putative dust contamination from the elevation mirror.

As of Sol 1931 (June 29, 2009), Opportunity's solar array energy production is 426 watt-hours. The atmospheric opacity (tau) is 0.488. The solar array has a dust factor of 0.529, indicating that 52.9 percent of sunlight hitting the array penetrates the layer of accumulated dust on it. Opportunity's total odometry is 16,712.46 meters (10.38 miles).

sol 1920-1926, June 18-24, 2009: Moving to Outcrop

Opportunity has been moving toward a candidate patch of rock outcrop in preparation for a rest of the mobility system over the coming holiday. There continues to be concern with the elevated motor currents seen in the right front wheel.

On Sol 1920 (June 18, 2009), Opportunity drove backwards about 63 meters (207 feet) south. The right front wheel currents were elevated but were not divergently increasing. After a few sols, Opportunity drove another 7 meters (23 feet) to a nearby outcrop.

Robotic arm activities on surface targets with the microscopic image (MI) and the alpha particle X-ray spectrometer (APXS) were performed on Sols 1924 and 1925 (June 22 and 23, 2009).

Further drives are planned to reach a large region of rock outcrop. Also, the week saw further implementation of the miniature thermal emission spectrometer (Mini-TES) mirror dust mitigation. The Mini-TES shroud is left open overnight to see if the environment will clean the elevation mirror.

As of Sol 1924 (June 22, 2009), the solar array energy production was 450 watt-hours with an atmospheric opacity (tau) of 0.480 and a dust factor of 0.530, indicating that 53 percent of sunlight hitting the solar array penetrates the layer of accumulated dust on the array. As of Sol 1926 (June 24, 2009), Opportunity's total odometry remains at 16,639.71 meters (10.3 miles)

sol 1913-1919, June 11-17, 2009: Dust Mitigation Effort

Opportunity has been stationary this week resting the right-front drive actuator. During this time, the rover is conducting a series of robotic arm (IDD) activities.

On Sol 1913 (June 11, 2009), the rover collected a set of microscopic imager (MI) sky flats to calibrate the camera images. Opportunity also began a mitigation effort for apparent dust on the elevation mirror of its miniature thermal emission spectrometer (Mini-TES). The mirror shroud will be left open to the environment overnight to allow the wind to clean some of the dust off.

On Sol 1915 (June 13, 2009), a Mars seismometry experiment was conducted using the rover's accelerometers. On Sol 1918 (June 16, 2009), Opportunity used the MI to collect images of target "Ios" before placing the alpha particle X-ray spectrometer (APXS) for an overnight integration.

As of Sol 1919 (June 17, 2009), Opportunity's solar array energy production is 416 watt-hours. Atmospheric opacity (tau) is 0.466. The dust factor is 0.524, indicating that 52.4 percent of sunlight hitting the solar array penetrates the layer of accumulated dust on the array. Opportunity's total odometry remains at 16,569.05 meters (10.3 miles).

sol 1906-1912, June 04-10, 2009: Elevated Wheel Current Again

Opportunity continues to drive south on the way to Endeavour crater. On Sol 1906 (June 4, 2009), the rover completed a 69-meter (266-foot) drive due south. Elevated actuator currents with the right-front wheel continue to cause concern. The rover rested for four sols before driving again, conducting observations with the panoramic camera (Pancam) and atmospheric argon measurements with the alpha particle X-ray spectrometer (APXS).

On Sol 1910 (June 8, 2009), the planned drive stopped early because a multi-wheel current limit threshold was exceeded. A diagnostic maneuver on the next sol was successful indicating the cause on the previous sol was due to the elevated right-front wheel motor currents. A long, backward drive was performed on Sol 1912 (June 10, 2009). Driving backwards is one technique to mitigate the elevated wheel currents. However, wheel currents continued to be elevated after that 72-meter (236-foot) drive. Further resting of the rover's actuators is being considered.

The plan ahead includes opening the shroud of the miniature thermal emission spectrometer (Mini-TES) to expose the instrument's dust-contaminated elevation mirror to the environment. This is an attempt to allow the wind environment to clean dust off the mirror.

As of Sol 1912 (June 10, 2009), Opportunity's solar array energy production is 431 watt-hours. Atmospheric opacity (tau) is 0.589. The dust factor is 0.549, indicating that 54.9 percent of sunlight hitting the solar array penetrates the layer of accumulated dust on the array. Opportunity's total odometry is 16,569.05 meters (10.3 miles).

sol 1900-1905, May 29 - June 03, 2009: Southbound Progress

Opportunity has been busy driving south. The rover drove four out of the last six sols. The drives have all been blind drives with regular slip checks for progress.

On Sols 1900, 1902 and 1904 (May 29, May 31 and June 2, 2009), Opportunity drove 66, 71 and 74 meters, (217, 233 and 243 feet), respectively. On Sol 1905 (June 3, 2009), the rover only accomplished about 30 meters (98 feet) of driving before the time ran out. Activities were very time-constrained on that sol.

Motor currents in the right-front wheel continue to be elevated. Limiting the drive distance and employing regular, short, backward slip checks seems to mitigate further increases in right-front wheel current.

As of Sol 1905 (June 3, 2009), Opportunity's solar array energy production is 413 watt-hours. Atmospheric opacity (tau) is 0.559. The dust factor is 0.542, meaning that 54.2 percent of sunlight hitting the solar array penetrates the layer of accumulated dust on the array. Opportunity's total odometry is 16,424.22 meters (10.2 miles).

sol 1893-1899, May 21-28, 2009: Passing The 10-Mile Mark

Opportunity is driving again, making good progress toward the distant Endeavour crater.

On Sol 1893 (May 21, 2009), Opportunity drove about 77 meters (252.6 feet) to the south. Motor currents in the right front wheel are elevated. After a few sols rest to collect atmospheric argon measurements with the alpha-particle X-ray spectrometer (APXS) and targeted Pancam observations, the rover drove about another 54 meters (177.2 feet). The right front wheel continued to show elevated current levels, but the levels are not increasing.

With its drive on Sol 1897 (May 25, 2009), Opportunity achieved another milestone, with its odometer surpassing the 10-mile mark (more than 16,093 meters)! Another drive on the next sol added another 50 meters (164 feet).

On Sol 1899 (May 28, 2009), the rover used its robotic arm (instrument deployment device, or IDD) to collect some sky flats (images of the sky) using its microscopic imager (MI). The sky images will be used for calibration purposes.

As of Sol 1899 (May 28, 2009), Opportunity's solar array energy production was 436 watt-hours, the atmospheric opacity (tau) remained around 0.651, and the dust factor was 0.564.

This week, Opportunity completed in-situ (contact) science with her robotic arm (IDD) on small pebbles located on an exposed rock outcrop.

On Sol 1886 (May 14, 2009), Opportunity collected a 5-stack of Microscopic Imager pictures then placed the Alpha Particle X-Ray Spectrometer on the target "Kasos." On the next sol, the rover placed the Mössbauer spectrometer on the same target for a multi-sol integration.

On Sol 1890 (May 18), Opportunity did something special to help out Spirit. The rover tested the technique of using the Microscopic Imager on the end of the IDD to image underneath the rover's belly pan, specifically examining her left middle and right middle wheels. Although the short-focus Microscopic Imager was never designed for such imaging, the images are of very good quality and show a fair amount of detail. Now that we know this technique can work, it may be tried on Spirit to determine if the rover is, in fact, high-centered on some rocks and to see if any obstruction of the left middle wheel can be observed.

With her in-situ work complete, Opportunity then drove about 20 meters (.01 miles) on Sol 1891 (May 19). A slight trend upward in the motor current for the right front wheel was noted. On Sol 1992 (May 20), Opportunity drove about 74 meters (243 feet), passing another milestone.

As of Sol 1891(May 19), Opportunity's solar-array energy production was 461 watt-hours, the atmospheric opacity (tau) remains around 0.613 and the dust factor is 0.557. Opportunity's total odometry as of Sol 1892 (May 20, 2009) is 16,003.33 meters (9.94 miles).

sol 1879-1885, May 07-13, 2009: Contact Investigation of Pebbles

Opportunity has been using its robotic arm (instrument deployment device, or IDD) to conduct a contact science investigation of small pebbles located on exposed rock outcrop.

On Sol 1881 (May 9, 2009), Opportunity took a special image with the microscopic imager of the left-front wheel. This tested a technique that might be used by Spirit to assess the state of Spirit's embedded wheels.

The alpha-particle X-ray spectrometer (APXS) was positioned on a pebble target for an overnight integration. On the next sol, the APXS was moved to a new target. On Sol 1884 (May 12, 2009), the rover backed away from these targets and then moved about 6 meters (20 feet) into a new position for more IDD work. The right-front wheel, which had shown elevated motor currents, exhibited improvement in the current levels after resting at these contact-science targets.

As of Sol 1884 (May 12, 2009), Opportunity's solar array energy production was 460 watt-hours, with atmospheric opacity (tau) around 0.732 and the dust factor at 0.581. Opportunity's total odometry as of Sol 1885 (May 13, 2009) is 15,908.93 meters (9.89 miles).

sol 1872-1878, April 30 - May 06, 2009: Study an Outcrop While Resting a Wheel

After moving around a troublesome ripple, on Sol 1872 (April 30, 2009) Opportunity performed a dog-leg maneuver heading south and achieving about 42 meters (138 feet) of distance. Electrical current levels in the right-front wheel have resumed larger-than-normal levels. The next drive, on Sol 1873 (May 1, 2009), was backward for about 50 meters (164 feet). The wheel currents remained elevated.

The project decided to take advantage of a contact-instruments science campaign to rest the actuator again. So on Sol 1877 (May 5, 2009), a short bump was performed to position the rover on exposed rock outcrop for the contact science. That work will proceed over the next several sols while the right front wheel actuator rests.

As of Sol 1877 (May 5, 2009), Opportunity's solar array energy production is 491 watt-hours, the atmospheric opacity (tau) remains around 0.811 and the dust factor is 0.609.

sol 1866-1871, April 24-29, 2009: Backing Off of a Ripple, Then a Rise in Wheel Current

Opportunity's drive on Sol 1865 (April 23, 2009) ended with the front wheels starting to dig into a large ripple. The first order of business this week then was to back off of the ripple and proceed down a different path. A backup drive on Sol 1866 (April 24, 2009) had only limited success as the rover moved only about 28 centimeters (11 inches) before limits stopped the drive. The drive on the next sol completed the backup, accomplishing 3.7 meters (12 feet) of movement.

Drives performed on sols 1870 and 1871 (April 28 and 29, 2009) totaled more than 64 meters (210 feet). The Sol 1871 drive showed a return of the increase in the amount of current drawn by drive actuator in the right-front wheel. The project is considering mitigation practices of resting the actuator and/or driving backwards for a while.

As of Sol 1865 (April 23, 2009), Opportunity's solar array energy production is 447 watt-hours. Atmospheric opacity (tau) is around 0.831. The dust factor is 0.607, meaning that 60.7 percent of sunlight hitting the solar array penetrates the layer of accumulated dust on the array. Opportunity is in good health, with an odometry total of 15,737.05 meters (9.78 miles).

sol 1852-1858, April 09-15, 2009: Crater Hopping

Opportunity has been crater hopping as the rover heads south, making drives between several small craters and taking drive-by images of them. These small craters -- just a few meters or yards in diameter -- are from fairly recent impacts, occurring in the last, maybe, 10,000 to 100,000 years.

Four drives were completed in the week, totaling more than 140 meters (459 feet). The drives were all blind drives. They used a mix of driving forward and driving backward. The longer drives included slip checks. Importantly, wheel currents have returned to more normal levels for the right-front wheel's drive actuator after it was rested for several sols following concerns about it drawing higher-than-usual current during drives in February and March.

As of Sol 1858 (April 15, 2009), Opportunity's solar array energy production is 491 watt-hours. Atmospheric opacity (tau) remains around 0.921. The dust factor is 0.615, meaning that 61.5 percent of sunlight hitting the solar array penetrates the layer of accumulated dust on the array. Opportunity is in good health, with an odometry total of 15,205.65 meters (9.45 miles).

sol 1844-1851, April 01-08, 2009: Cleaning Event Boosts Energy

Opportunity completed a contact science campaign on an exposed rock outcrop and then resumed driving.

On Sol 1845 (April 2, 2009), the rover's robotic arm (IDD) placed the Mössbauer (MB) spectrometer on the outcrop target "Penrhyn" for a multi-sol integration. On Sol 1850 (April 7, 2009), a temporary stand-down on driving was provisionally lifted and Opportunity resumed driving. The MB was retracted and the arm moved into the driving stow position. Opportunity then drove backward about 62.5 meters (205 feet). Diving backward was a continuation of mitigation techniques used in recent weeks in response to elevated current observed in the right-front wheel. The mitigation also has included resting the drive actuator for several sols, which coincided with the just-completed contact science campaign. The drive went well and the right-front actuator exhibited currents near normal levels, good news.

Opportunity also benefited from a solar array cleaning event which boosted energy levels by about 40 percent, a big increase. Now if only Spirit could get such a cleaning.

As of Sol 1850 (April 7, 2009), Opportunity's solar array energy production has increased to 515 watt-hours. Atmospheric opacity (tau) remains elevated at around 0.95. The dust factor has improved to 0.642, meaning that 64.2 percent of sunlight hitting the solar array penetrates the layer of accumulated dust on the array. The rover is in good health with a rested actuator and extra energy.

Opportunity remains positioned on an exposed rock outcrop and is continuing a contact science campaign with the robotic arm (IDD). On Sol 1838 (March 26, 2009), the rock abrasion tool (RAT) was operated for 3 hours to grind 3 millimeters (one-tenth of an inch) into the selected rock outcrop target. The grind, using the work-around for the failed encoder, worked as sequenced. Documentary imagery was collected of the new RAT hole. Then the Mössbauer (MB) spectrometer was placed in the RAT hole for a long integration. On Sol 1840 (March 28, 2009), stereo imagery by the microscopic imager (MI) was collected and the MB positioned for further readings. On Sol 1843 (March 31, 2009), after a few sols of MB integration, images documenting the MB placement on the RAT tailings were collected and then the alpha particle X-ray spectrometer (APXS) was placed on the target for its integration.

As of Sol 1843 (March 31, 2009), Opportunity's solar array energy production is 346 watt-hours, equivalent to the amount used by a 100-watt bulb lit for about three and a half hours. Atmospheric opacity (tau) remains elevated at 1.20. The dust factor on the solar array has improved slightly to 0.512, meaning that 51.2 percent of sunlight hitting the solar array penetrates the layer of accumulated dust on the array. Both rovers are experiencing elevated atmospheric opacity as large storms to the south generate a lot of high-altitude dust.

Opportunity is in good health, with total odometry remaining at 15,051.44 meters (9.35 miles).

On Sol 1832 (March 20, 2009), the first part of a rock abrasion tool (RAT) brushing activity was performed. Using a new work-around for the failed RAT Z-encoder, the RAT successfully performed a seek-scan to locate the rock surface. On the next sol, the RAT successfully brushed the surface. The Microscopic imager (MI) took images to document the brushing. The Mössbauer (MB) spectrometer was placed on the brushed target, and several sols of integration were performed. On Sol 1836 (March 24, 2009), the alpha particle X-ray spectrometer (APXS) was placed on the brushed target to measure the elemental composition. On Sol 1837 (March 25, 2009), another RAT seek-scan was performed to set up for a RAT grind on the next sol.

As of Sol 1837 (March 25, 2009), Opportunity's solar array energy production is 336 watt-hours. Atmospheric opacity (tau) remains elevated at 1.145. The solar array dust factor is 0.497, meaning that 49.7 percent of sunlight hitting the solar array penetrates the layer of accumulated dust on the array. Opportunity is in good health. Its total odometry remains at 15,051.44 meters (9.35 miles).

sol 1824-1831, March 11-19, 2009: At Outcrop with Endeavour in Sight

Opportunity has positioned itself at an exposed rock outcrop and is in the middle of an "in situ" (contact) science campaign with the robotic arm (IDD). Because of the project team's desire to rest the right-front wheel actuator and to limit driving while an earlier drive sequence error is remedied, Opportunity took advantage of the nearby rock outcrop. This fits with the strategic science campaign to periodically stop and "taste" the geology along the route to Endeavour crater.

Part of the rim of Endeavour can now be seen on the distant horizon.

On Sol 1824 (March 11, 2009), Opportunity drove about 5 meters (16 feet) to the exposed rock outcrop. The rover bumped (fined tuned its location) only about half a meter (1.5 feet) on the next sol to reach a position where surface targets are within the reach of the IDD. Because of the degraded IDD Joint 1 (shoulder azimuth), positioning the IDD has become more challenging, but it was accomplished successfully.

On Sol 1826 (March 13, 2009), Opportunity began the IDD work, first with a Mössbauer spectrometer (MB) touch, then with a microscopic imager (MI) mosaic. On Sol 1829 (March 17, 2009), additional MI mosaics were collected, followed by the placement of the MB for several sols. Additional ground testing was completed to prepare for the first use of the rock abrasion tool (RAT) since the earlier failure of another of its encoders.

As of Sol 1831 (March 19, 2009), Opportunity's solar array energy production has dipped to 391 watt-hours in connection with atmospheric opacity (tau) increasing to 0.934. The dust factor on the solar array is 0.533. The rover is in good health. Opportunity's total odometry is 15,051.41 meters (9.35 miles).

sol 1818-1824, March 04-11, 2009: Driving Anomaly

Opportunity experienced a serious drive sequence error on Sol 1820 (March 7, 2009). Because of elevated right front wheel currents, Opportunity has been driving backwards towards its goals. On Sol 1820, Opportunity was to perform a short approach to a stand-off distance near a small crater, called "Resolution." Due to an unanticipated interaction between a test of an onboard sequence and the planned drive sequence, Opportunity did not drive backwards toward its goal. Instead, the rover drove forward some distance before stopping.

The rover is fine and situated in safe terrain. The project is investigating this anomaly and has isolated the problem to the test of that onboard sequence. Further corrective action is being implemented to guard against this type of unanticipated sequence interaction.

As of Sol 1824 (March 11, 2009), Opportunity's solar array energy production is 454 watt-hours. Atmospheric opacity (tau) has increased a little to 0.745. The dust factor on the solar array is 0.550, meaning that 55 percent of sunlight hitting the solar array penetrates the layer of accumulated dust on the array. The rover is in good health. Opportunity's total odometry is 14,963.26 meters (9.30 miles).

sol 1811-1817, February 26 - March 04, 2009: New Software Working Fine

Opportunity continues to exhibit elevated motor current in the drive actuator of the right-front wheel. To mitigate this, the rover has been driving backward.

This week, Opportunity built and booted new flight software, version R9.3. After a build activity on Sol 1811 (Feb. 26, 2009), Opportunity booted onto the R9.3 flight software on Sol 1814 (March 1, 2009). The new software has been working fine.

Opportunity drove more than 56 meters (184 feet) the sol before the boot and drove again for about 40 meters (131 feet) on Sol 1816 (March 3, 2009), two sols after the boot. The team is considering resting the right-front drive actuator in coming sols as a way to further mitigate the elevated motor current.

As of Sol 1817 (March 4, 2009), the solar array energy production is 488 watt-hours, down by 20 watt-hours from a week earlier. Atmospheric opacity (tau) has increased a little to 0.710. The dust factor on the solar array is 0.576, meaning that 57.6 percent of sunlight hitting the solar array penetrates the layer of accumulated dust on the array. The rover is in good health using its new flight software.

Opportunity has been exhibiting elevated motor current in the right-front wheel's drive actuator. To investigate this, the team put the rover through a set of diagnostic maneuvers. On Sol 1803 (Feb. 18, 2009), Opportunity performed a series of arcs on differing terrain, then turned around and drove backward, traveling about 55 meters (180 feet) in all. The right-front wheel current remained elevated, although that was expected. On Sol 1806 (Feb. 21, 2009), the rover drove backward about 61 meters (200 feet). The near-term plan is to drive backward to facilitate reflow of lubricants within the right-front actuator gear box.

On Sol 1809 (Feb. 24, 2009), the team began the process of building and booting a new version of the rover flight software, version R9.3. This will be a multi-sol process. Driving will be precluded until the rover's boot up onto R9.3.

As of Sol 1809 (Feb. 24, 2009), Opportunity's solar-array energy production has dipped slightly to 508 watt-hours, enough to light a 100-watt bulb for just over 5 hours. Atmospheric opacity (tau) has increased to 0.640. The dust factor on the solar array is 0.563, meaning that 56.3 percent of the sunlight hitting the solar array penetrates the layer of accumulated dust on the array. The rover is in good health as it gets ready for new software. Opportunity's total odometry is 14,737.41 meters (9.16 miles).

sol 1797-1802, February 12-17, 2009: Checking the Right-Front Wheel

Opportunity is continuing with a series of long drives. The drive on Sol 1797 (February 12, 2009) achieved 111 meters (364 feet). During the drive the right-front wheel exhibited higher-than-usual motor currents. Since April 2005, Opportunity's right-front wheel has had a jammed steering actuator, with the wheel turned inwards about 7 degrees from straight ahead, so it works harder on some drives. On Sol 1800 (February 15, 2009), the rover conducted a series of mobility diagnostic drives to study the right-front wheel. The rover turned around and drove backward about 10 meters (31 feet), turned around again and drove forward about 11 meters (36 feet), and then performed an arc of about 4 meters (13 feet). The wheel currents were monitored.

The plan for the near term is to drive backward to see if that improves performance of the right-front wheel, although backward driving will limit the distance traveled each sol.

As of Sol 1802 (February 17, 2009), Opportunity's solar-array energy production is 567 watt-hours. Atmospheric opacity (tau) has moderated to 0.540. The dust factor on the solar array is 0.589, meaning that 58.9 percent of the sunlight hitting the solar array penetrates the layer of accumulated dust on the array. The rover is in good health.

Opportunity is continuing with a series of long drives that employ an initial segment of blind driving followed by a segment under D-star global navigation. This combination technique has been successful in achieving safe, long drives. On Sol 1791 (February 6, 2009), Opportunity achieved only about 27 meters (89 feet) due to a small veer into a keep-out zone, which terminated the drive. On Sol 1793 (February 8, 2009), almost 58 meters (190 feet) of driving was achieved before the rover encountered a terrain situation where its global navigation software was unable to find a safe solution to proceed. Driving resumed on Sol 1795 (February 10, 2009) with a 136-meter (446-foot) drive. That was followed by a 123-meter (404-foot) drive on the next sol.

As of Sol 1796 (February 11, 2009), Opportunity's solar-array energy production is 565 watt-hours, enough to light a 100-watt bulb for more than five hours. Atmospheric opacity (tau) increased slightly to 0.584. The dust factor on the solar array is 0.600, meaning that 60 percent of the sunlight hitting the array penetrates the layer of accumulated dust on the array. The rover is in good health. Opportunity's total odometry is 14,482.63 meters (9.00 miles).

Opportunity began the week with a series of planned long drives. On Sol 1784 (January 29, 2009), Opportunity drove 88 meters (289 feet) using a combination of blind driving for the first part, then switching to autonomous driving using D-star global navigation. On Sol 1786 (January 31, 2009), another long drive was sequenced using the same drive strategy. However, during the autonomous portion of the drive a fault occurred in the camera-mast assembly, which terminated the drive. Subsequent investigation was frustrated by a delay in the return of telemetry due to Earth-based weather problems. Once the data were reviewed it was discovered that a single event upset had occurred in the mast assembly. Such single event upsets occur from time to time on each rover, and on other spacecraft, due to cosmic rays. The mast assembly is otherwise OK. The plan ahead is to initialize the mast assembly and resume driving.

As of Sol 1790 (February 4, 2009), Opportunity's solar-array energy production is 589 watt-hours (enough to light a 100-watt bulb for nearly 6 hours). Atmospheric opacity (tau) is 0.400, a slight improvement from a week earlier. The dust factor on the solar array is 0.591, meaning that 59.1 percent of the sunlight hitting the solar array gets past the accumulated dust on the array. Opportunity is in good health. Its total odometry is 14,138.20 meters (8.79 miles).

sol 1777-1782, January 22-27, 2009: Five Years and 14 Kilometers

Opportunity spent its fifth-anniversary week making more progress in its long trek toward Endeavour crater. After completing an imaging survey of "Ranger" crater and collecting atmospheric argon measurements with the alpha particle X-ray spectrometer, the rover on Sol 1780 (January 25, 2009) drove 50 meters (164 feet) to the south-southeast. Two sols later, using its D-star global navigation, Opportunity completed a 130-meter (427-foot) drive also to the south-southeast, with mid-drive imaging. This drive put Opportunity's total odometry over 14 kilometers since landing 5 years ago.

As of Sol 1782 (January 27, 2009), Opportunity's solar-array energy production is 570 watt-hours, enough to light a 100-watt bulb for nearly six hours. Atmospheric opacity (tau) is 0.483, slightly higher than it was a week earlier. The dust factor on the solar array is 0.609, meaning that 60.9 percent of the sunlight hitting the solar array penetrates the layer of accumulated dust to generate electricity. The rover is in good health. Opportunity's total odometry is 14,047.76 meters (8.73 miles).

sol 1770-1776, January 15-21, 2009: Happy Anniversary!

Happy anniversary to both Spirit and Opportunity for completing five Earth-years exploring the surface of Mars!

Opportunity's goal this past week has been to put the pedal to the metal and acquire drive-by images of a crater dubbed "Ranger Crater."

Preliminary results from last week's shake of the mirror on the miniature thermal emission spectrometer on sol 1771 (Jan. 16, 2009) indicated that no dust was removed as engineers had hoped.

Opportunity is healthy, and all subsystems are performing as expected as of the downlink of information on sol 1776 (Jan. 21, 2009). Solar energy levels are at 613 watt-hours (slightly more than the amount of energy needed to light a 100-watt bulb for six hours). Tau, a measure of sunlight-blocking dust in the atmosphere, is 0.455. The dust factor, a measure of the proportion of sunlight penetrating dust on the solar arrays, is 0.6196.

Sol-by-sol summary

In addition to monitoring daily dust-related changes in atmospheric clarity with the panoramic camera and relaying data to NASA's Mars Odyssey orbiter for transmission to Earth, Opportunity completed the following activities:

Sol 1770 (Jan. 15, 2009): Opportunity drove and acquired image mosaics with the navigation and panoramic cameras. The rover measured argon gas in the Martian atmosphere using the alpha-particle X-ray spectrometer and went into a mini-deep sleep.

Sol 1771: Opportunity completed a systematic foreground quarter survey using all 13 color filters of the panoramic camera. The rover checked for drift (changes with time) in the miniature thermal emission spectrometer, conducted a utility test of the instrument, and completed a post-shake test calibration by looking at the ground and sky. Opportunity measured argon gas in the Martian atmosphere using the alpha-particle X-ray spectrometer and went into a mini-deep sleep.

Sol 1772: Opportunity surveyed the sky at low Sun with the panoramic camera and, after relaying data to Odyssey, measured argon gas in the Martian atmosphere using the alpha-particle X-ray spectrometer. The rover went into a mini-deep sleep.

Sol 1773: Opportunity took morning, thumbnail images of the sky with the panoramic camera and full-color images, using all 13 filters of the panoramic camera, of a target dubbed "Thassos." The rover acquired a 6-by-1 panel of images of pavement textures using the panoramic camera. After measuring argon gas in the Martian atmosphere using the alpha-particle X-ray spectrometer, Opportunity went into a mini-deep sleep.

Sol 1774: Opportunity drove 115.36 meters (378.48 feet) and acquired new image mosaics with the navigation and panoramic cameras, including a 360-degree view with the navigation camera. After the day's activities, the rover went into a deep sleep.

Sol 1775: In the morning, Opportunity surveyed the sky at high Sun with the panoramic camera. The rover completed a systematic foreground quarter survey with all 13 color filters of the panoramic camera. After relaying data to Odyssey, Opportunity measured argon gas in the Martian atmosphere using the alpha-particle X-ray spectrometer and went into a mini-deep sleep.

Sol 1776 (Jan. 21, 2009): In the morning, Opportunity took spot images of the sky with the panoramic camera for calibration purposes. Opportunity drove 29.90 meters (98.10 feet) to approach Ranger Crater and completed a quick get fine attitude to check the rover's precise location relative to the Sun. The rover acquired new image mosaics with the navigation and panoramic cameras and took a Tau measurement of atmospheric dust at sunset. Opportunity then went into a deep sleep. The following morning, Opportunity was to take spot images of the sky for calibration purposes with the panoramic camera, acquire time-lapse movie frames in search of clouds with the navigation camera, and monitor dust accumulation on the panoramic-camera mast assembly.

Opportunity's drivers have established that the encoder that controls the up-and-down (z-axis) movement of the rover's rock abrasion tool (RAT) has indeed failed, as first suspected and reported last week. Engineers responded by "caging the RAT," so to speak, homing the instrument back into a safe position so as to avoid damage from debris during driving. Opportunity prematurely halted the first attempt to do this when a position check showed the precise position was unknown. Engineers resolved the issue by calibrating the RAT prior to the homing activity. In the coming weeks, they will be developing and testing a work-around to support future RAT activities.

This week, Opportunity also performed a "shake test" on the miniature thermal emission spectrometer. In the shake test, low-level motor commands create a short vibration to shake dust from the instrument's external scan mirror. Two previous tests, one lasting for 3 seconds and the other for 6 seconds, produced no measurable improvement. This week's vibration test lasted for 21 seconds and scientists are now analyzing the results.

Prior to resuming the drive to Endeavour Crater, Opportunity wrapped up remote-sensing activities at the rover's current location. These included taking panoramic-camera images of cobbles and targets known as "Samos" and "Corsica," monitoring dust on the rover mast, and studying the atmosphere.

Opportunity is healthy, and all subsystems are performing as expected as of the downlink of information on sol 1769 (Jan. 14, 2009). Power remains very healthy, averaging just more than 597 watt-hours (almost the same amount of energy needed to light a 100-watt bulb for six hours).

Sol-by-sol summary

In addition to monitoring daily dust-related changes in atmospheric clarity with the panoramic camera and relaying data to NASA's Mars Odyssey orbiter for transmission to Earth, Opportunity completed the following activities:

Sol 1764: Opportunity "caged the RAT," retracting the rock abrasion tool along its Z-axis for protection, and acquired full-color, panoramic-camera images of cobbles. In addition to measuring atmospheric opacity caused by dust with the panoramic camera, Opportunity assessed atmospheric opacity with the navigation camera. The rover took spot images of the sky with the panoramic camera for calibration purposes.

Sol 1765: In the morning, Opportunity took thumbnail images of the sky with the panoramic camera, and after sending data to Odyssey, measured atmospheric argon with the alpha-particle X-ray spectrometer.

Sol 1766: Opportunity started the day by assessing dust accumulation on the panoramic-camera mast assembly, scanning the sky for clouds with the navigation camera, and taking spot images of the sky with the panoramic camera. At midday, the rover surveyed the sky at high Sun with the panoramic camera. Opportunity again scanned the sky for clouds, acquired panoramic-camera images looking ahead in the drive direction, checked for drift (changes with time) in the miniature thermal emission spectrometer, tested the utility of the spectrometer and scanned the ground and sky with the instrument before conducting a shake test. The rover then vibrated the miniature thermal emission spectrometer as planned, shaking and shimmying it seven times. After sending data to Odyssey, Opportunity measured argon gas with the alpha-particle X-ray spectrometer.

Sol 1768: Opportunity again "caged the RAT," as described above, and took super-resolution images of Corsica with the panoramic camera. The rover checked for drift in the miniature thermal emission spectrometer, tested the utility of the instrument, and scanned the ground and sky for a post-shake test calibration to determine if the procedure resulted in any improvement. Opportunity also measured atmospheric argon.

Sol 1769 (Jan. 14, 2009): Opportunity continued to measure argon gas in the atmosphere with the alpha-particle X-ray spectrometer and recharged the batteries.

Odometry

As of sol 1769 (Jan. 14, 2009), Opportunity's total odometry remained at 13,617.33 meters (8.46 miles).

As Opportunity was preparing to brush the surface of a rock exposure called "Candia" (Italian for Crete), the rock-abrasion tool stalled. The stall occurred on the rover's 1,759th sol, or Martian day (Jan. 4, 2009), of exploration, as Opportunity was lowering the instrument to locate the rock's surface. Engineers are concerned that the stall could indicate a failure of the encoder that controls the z-axis (up-and-down) movement of the rock-abrasion tool. The encoder provides precise position and motion direction to the rover's computer controllers.

Engineers have been anticipating the eventual loss of the encoder as a result of earlier electrical issues. Opportunity already lost the encoders that control the revolving of the grind bit and the grinding motion as a result of wear and tear on the flex cable. (The flex cable is the flat "ribbon" of electrical cable that runs down the length of the rover's robotic arm.) On sol 1762 (Jan. 7, 2009), engineers tested the encoder by directing Opportunity to extend the rock abrasion tool downward and take images before and after the maneuver to document potential motion. Engineers did detect motion in the images, and data they received from the encoder was what they expected for a failure. In coming weeks, they will attempt to devise a work-around technique. Meanwhile, they decided to forego brushing this particular rock target and get Opportunity back on the road to Endeavour Crater.

Opportunity conducted a variety of remote-sensing observations during the past week. Highlights included: Full-color, 13-filter, panoramic-camera images of Candia and a nearby rock exposure nicknamed "Gavdos," cobbles dubbed "Kythira" and "Samos," and a soil target called "Minos." Opportunity took images of the rover's deck, studied the composition of soil exposed in the rover's wheel tracks, and measured argon gas in the atmosphere.

Opportunity is healthy. With the exception of the rock-abrasion tool, all subsystems are performing as expected as of the downlink of information from sol 1762. Power continues to be very good, averaging just over 600 watt-hours (equivalent to the amount of energy needed to light a 100-watt bulb for six hours each day).

Sol-by-sol summary

In addition to monitoring daily dust-related changes in atmospheric clarity with the panoramic camera and relaying data to NASA's Mars Odyssey orbiter for transmission to Earth, Opportunity completed the following activities:

Sol 1757: Opportunity continued to collect data on the composition of Minos. The rover surveyed the horizon with the panoramic camera.

Sol 1758: Using all 13 filters of the panoramic camera, Opportunity took full-color images of the rover's tracks. Using the alpha-particle X-ray spectrometer, Opportunity resumed measurements of chemical elements in the soil target known as Minos.

Sol 1759: Opportunity moved the robotic arm, took full-color panoramic-camera images of Candia, panoramic-camera images of the nose of the Mössbauer spectrometer, and attempted to lower the rock-abrasion tool to the surface of Candia. The rover took thumbnail images of the sky with the panoramic camera, measured atmospheric argon with the alpha-particle X-ray spectrometer, and surveyed the horizon with the panoramic camera.

Sol 1761: In the morning, Opportunity took thumbnail images of the sky with the panoramic camera. Later, the rover took images of cobbles of scientific interest with the navigation camera. Opportunity acquired full-color images, using all 13 filter of the panoramic camera, of Samos and Kythira. After communicating with Odyssey, the rover measured argon gas in the atmosphere with the alpha-particle spectrometer.

Sol 1762 (Jan. 7, 2009): In the morning, Opportunity surveyed the sky with the panoramic camera. After measuring dust-related changes in atmospheric clarity with the panoramic camera, Opportunity ran diagnostic tests of the rock-abrasion tool. Opportunity also measured atmospheric argon. Plans for the following morning called for the rover to measure dust-related changes in atmospheric clarity with both the panoramic and navigation cameras and take spot images of the sky for calibration purposes with the panoramic camera.

Odometry

As of sol 1762 (Jan. 7, 2009), Opportunity's total odometry remained at 13,617.33 meters (8.46 miles).